Heat treating furnace tray



Feb. 28, 1939. H. H, HARRIS HEAT TREATING FURNACE TRAY Filed Deo. 18, 1937 INVENTOR. HemfyH. HarrS @Zumal '.latented Feb. 28, 1939 UNITED STATES mrs oFFlcE invention relates to heat treating furnaces, and particularly to heatond corrosion resisting alloy members used therein, especially the rails und the trays which travel upon the rails and It carry loads of the work to' be heat treated, an-

nealed, and the like. f

'The present invention is in part an improve-l ment on my Patent No. 2,il22,2tt, granted Novemher 2t, i935.

y e the arrangement shown in the drawing oi my said patent, and consisting ol two tray portions hinged together and travelling, `with or without an underlying shoe, upon three rails, is a great advantage over prior practice in which the hinge arrangement was lacking, I have found that improvement could be made therein in several rpects as will be pointed out.

With a furnace containing three longitudinal rails as shown in the drawing o f said patent, each tray portion must span substantially half the furnace width and must be made correspondingly strong and comparatively heavy. When the underlying shoe arrangement is provided, this .shoe is an extra part to be made and for which d material must be supplied, and yet the shoe periorms no work-carrying function.

By the present invention I provide an odd number of tray portions, three tray portions being slrown lor purposes of illustration. One oi' the tray portions is centrally disposed, and the others are wing trays hingedly related thereto at eachside. The trays and the rails on which they ltravel are made as castings of heat and corrosion resisting alloy, preferably iron, chromium and nichel alloy.

c central tray portion carries its share of the worin and is mounted to travel on a plurality oi rails, two rails being shown for illustration. l also provide wing tray portions hinged to 'the central portion, or hinged to a tray portion which 'is hinged to the central portion, and each Wing tray portion is traveled over one or more rails, one such rail being shown for illustration.

lil

th such arrangement all the sections of the tray periorm useiul load-carrying work. The

M ported uniformly by the rails, there being no.

spanning or stid, rigid tray sections across an intermediate rail to rest only thereon if the rail should be bulged up or otherwise raised, or to fail `to make contact with such intermediate rail, if it or parts of it should be depressed below the rail portions on either side.

lin my drawing,

Iliig. l is a plan view of the hinged tray in three portions or sections;

Fig. 2 is a section taken lengthwise of the tray formation of Fig. 1;

Fig. 3 is a section on line 3-3 ol Fig. l; and

Fig. 4 is a section on line l-Jl of lig. l.

The central tray portion is indicated by reference numeral l0, its bottom I2 being preferably of light skeleton formation, and guard rails il, lil being provided to retain work placed thereon.

The central tray portion i is traveled along the rails by pushing, or otherwise. This tray portion is supported by a plurality of rails, preferably two rails I8, I8. Skid rails are shown, but roller rails can also be used.

The central tray portion or section i0 is preferably cast or otherwise formed with bearing and laterally stiilening members 20, 22 to ride on the rails It, i8, and also to transmit pushing stresses should the furnace be of the pusher type wherein trays are traveled along by pushing from behind as new trays are inserted into the furnace.

Means are provided for guiding and retaining the central tray portion I0 on the rails, as for example, support member 20 may be provided with downwardly extended lugs 2l which project down on each side of rail 2li, and these lugs 23 may have outer enlarged faces 23' to give extended pushing contact area.

Single wing tray portions 24 and 28 are shown in the drawing hinged one on each side to the central tray portion i0. These tray portions, as also tray portion lil, are preferably made with skeleton bottoms to permit free access of heat and f urnace gases to the worlrcarried thereby, and are also provided with guard rails il to keep work from slipping od. The illustrated hinging connection consists of pins it, 29 passing loosely through the bar portions 30, 30 oi' tray portion It and through bar portions 32, 32 and 34, 34 of the wing tray portions 2l and 2B respectively.

The bar portions 30, 32 and 34 are preferably so spaced that the hinge connection, in addition to loosely 'hinging the parts together, serves to prevent lateral displacement between tray portions in the direction of travel. The arrangement shown for this purpose consists of arranging two of the bar portions l2 and 34 of trays 24 and 26 respectively between apair of the bar portions 20 of the central tray portion l0. One rail 36 is shown for supporting the outer end of wing tray portion 24, and another rail 36 for supporting the opposite and also outer end of tray portion 26.

The wing tray portions 24 and 26 are provided, towards the outer ends thereof furthest from their hinge connections, with bearing portions 44, 46, respectively, to ride on rails 36 and 36 and to give stiffness to the structure as when being pushed through the furnace.

It is sometimes necessary to lift the trays and loads as by means of hoists or the like. It is oi assistance in this connection to be able to attach the hoisting hooks or other lifting devices to each end of the tray structure. Accordingly I provide hinging limit means such as the hooks 40, 42 on the wing tray portions 24 and 26 to catch under the supporting bearing bars 20, 22 of central tray I0. When the tray structure is lifted by its extreme ends, all the tray portions and their loads are lifted together with only the central tray portion sagging somewhat, `the hooks 40, 42 engaging the under sides of the vbearing bars 20, 22.

While I have shown but one central tray portion and one wing tray portion on each side, or three tray portions in all constituting the entire tray, other odd numbers of tray portions can be used, as five tray portions (not shown), the additional wing tray portions being hinged to the outer ends of each of the wing tray portions 24, 26.

I claim:

1. 'I'he combination, in heat treating trays, of a central tray portion having bearing portions adapted to travel on a. plurality of rails, with a pair of tray portions, one of which is hinged to the central tray portion at each side thereof, and each oi' said last named tray portions being provided with a bearing portion near its outer side adapted to travel on a single rail.

2. In heat-treating trays, the combination of a central tray portion having bearing portions adapted to travel on a plurality of tracks and provided with means to retain and guide the tray portion on at least one of the tracks, a side tray portion hinged to one side of said central tray portion, a second side tray portion hinged to the opposite side oi' said central tray portion, each of said side tray portions being provided with bearing surfaces adapted to travel on a single rail.

3. A central tray portion, and two side tray portions, one thereof hinged to each side of the central tray portion, and hinging limit hook means adapted to limit the turning movement at the hinges, whereby the complete three-portion tray can be picked up by elevating means applied to the ends thereof.

4. In heat treating trays, the combination of an openwork central tray portion, an openwork side tray portion loosely hinged to the central tray portion at one side, an openwork side tray portion loosely hinged to the central tray portion at the opposite side, and hooks depending from each-of the side tray portions and projecting beneath a part of said central tray portion, Whereby, when the side tray portions are lifted, the central tray is also lifted therewith.

HENRY H. HARRIS. 

